Railway signaling system



' Nov. 27, 1 23. 1,475,388

A. EJHUDD RAILWAY SIGNALING SYSTEM Filed Jam.- 4, 1921 2 Sheets-Sheet 1 F16. y I A A 1-H. I""\ V a 1 l r,

Nov. 27, 1923.

A. E. HUDD RAILWAY SIGNALING SYSTEM Filed Jan. 4, 1921 2 sa as-5W F/a/A.

Patented Nov. 27, 1923.

ALFRED nannsr HUDD. or LIVERPOOL, nnenaniigassreiiorlro AUTOMATIC TELE- "PHONEVMANUFACQDURING co vrraaw LIMITED, or; LIVEBPOOL, 'EI\IGLAND.'

RAILWAY srenemns SYSTEM.

Application filed January 4, 1921. Serial No. 434,927.

To all 107mm it may concern.

'Be' it known that ALFRED: Ennns'r HUDD a,

subjeet of the King of GreatBritain, re-I siding at Stoneleigh Orient'Drive, Gates ac're, Liverpool; England, has invented 'cer tain new andus'eful Improvements 1n Ra1lway' Signaling Systems, "or following is a specification. A v The present inventionr'elates to improvements "1n and relating to rallw'ay signa'llng systemsand has'fo'r its objecta" simplifiedf arrangement of track signaling which can be readily applied to" tracks of considei'able w Y J' V: v

In'all railway tracks, there is a considerable amount of electrical] leakage between. the "rails; and consequently, it the block is very long andrur'rent continuouslyjapplied thereto,'a consider-able loss is incurred,='

and if batteries areused to give a diree't'cur rent supply, thesdr'zipi'd-ly become exhausted. According to the prese t invention, sig nals or like devices controlling passage of the trains are in turn controlled by means of momentary currents "transmitted through the track. Preferably, the momentary cur rent transmitted through the track'is adapted to set in'a'ction a local track circuit, which is adapted to control the-signal" or other ap aratus, a

K-T-he invention will be better understood by referring to the accompanying drawings; in which Figures land'l show the 'applica titinof the invention to a double tracksys tern while Figures 2 and 2 showthe appli cation of the i invention to asingle track system.

It will be understood that these arrangements are only shown by way of example, as considerable n odifications=may be made therein withoutdeparting irom the spirit of the' inve'ntion, when applied'to' otherop'en ati'ngconditionsl "For instance; the signals are allf'described -as being'of the two posi-' tion type'ivhic'hindicate danger:- whenhori- Zontal-and' clear whe'n lowered'to an angle of 45 pointing downwardl altho; obviously, other signals could be employed without dek parting from the spirit of the invention "Beterring'to Figures 1 and 1}? two stations A and B are shown and the apparatus for one direction of train movement only is shown, that is to say, for trains moving in the direction from; B to A on the lower track 1 The main track between A and B is formed into a section by the insulators 2 and 3, while at station B, a short length of the lower track is insulated from the main" portion *by the insulator 4. is

The invention will be better understood by describing the'o-pera-tion of the system. Assuming that the signal man'at station B desires the signal man at station A to accept i a train. To do this, he operates his tapper keyh, sending positive current from earth E battery 6 b'ac-kflcontaot of armature 7 of looal-track relayS, operating contact of tapper key 5,iline-9 ,i (which iswan independent line running between stations A and B andis used solely-tor. the purpose of intercom-v munication between the signal boxes but has no control whatever overthe actual operation of the signalsharesting contact of tapperkey 1O atstationA, bellill, indicator12 to earth Inthis circuit,the bell llurings. while the indicator 12 which is polarized does not operate with current in this direction,- then the signal man at-station A, to accept the train, presses 'thepush button 13 thereby closingthe following circuit over the track. Negative pole of: battery 14:, lower rail of track 1, switch 15 controlled by the starting signa'l lever, track relay 16;

upper rail of track 1, push-button 13in operated position to positivesideof battery 14:. The operation of relay 16 then depends upon whether there is a train or otherwise on the main portion. of the track between A and B, if there is a'trainithe relay 16 will be short circuited and :will' not operate, wherea s-,.-it there is no train or similar obstacle, the relay 16 will: ,obtain enough current to energize and cause its armature 17".to m'a'ke contact with the-front contact.- The closure of this contact; them connects battery 19 between the locally insulated po'rtionlS of the lower rail of. thefltraek 1. and the upper rail. Then if the local track is clear of either train or obstruction, a circuit would be closed for thelocaltrack relay v8 in seriesw-ith the springs 20 of a release key 21 which is pro vided for a purpose to be explained later. The relay 8 operates and at its armature 22, locks itself on the local track circuit; consequently the signal transmitted over the line may be only transitory and the relay 16 only momentarily energizes. At its armature 23, the line indicator 24 is connected in series with battery 25, so that the line indicator attracts its armature to show train accepted. At armature 26, a circuit is prepared for the signal reverser 27 the signal reverser, which is essentially an electromagnetic clutch for connecting the chain controlled by the signal lever with the signal proper, may be of any known type. The circuit for the reverser 27 is completed by the signalman'pressing the push button 100 and then operating the signal lever, which causes the signal to be lowered; subsequently the circuit of the signal reverser is closed in dependently of the push 100 through the start-ing signal lever contacts 29. At armature 7, negative battery 30 is connected to the operative contact of tapper key 5, so that when the signal man at B operates his tapper key to signify that he has receivedthe acceptance signal, negative current is transmitted over the line 9. This causes the bell 11 to operate as before and also the polarized indicator 12 which attracts its armature to show train accepted. At the same time, the Signalman at B lowers the signal to accept the train.

The train, on entering the first part of the track, short circuits the upper rail and the insulated portion 18 of the lower rail, whereby the relay 8 de-energizes and the circuits made by armatures 22, 23, 26 and 7 are again broken The de-energization of the signal reverser 27, causes the signal to return to danger, the de-energization of the line indicator 24, causes the armature to fall back against the mechanical latch 31, thereby showing train on line. The release of the armature 22 opens the looking circuit of the relay 8 so that this cannot I whereby the armature of the indicator 12' again pick up until the relay 16 has been operated, which cannot take place until the train has passed A and B; when this occurs,

the signalman at A presses the push but-ton 32 to operate the mechanical, latch 33 is allowed to fall againstthe stop 35 to its normal position to show line closed. At the same time, the Signalman operates his bell tapper key 10 and sends a code of rings to the Signalman at B to ring his bell 36,

the current being without effect on his line indicator 3? in this direction. The signalman at B thenpresses hispush-butto-n 38 to operate the mechanical latch 31 to allow his indicator 24 to return to the normal position and also shows line closed.

It will thus be appreciated, that by means lower the si nal if there is a train on the section A 4:033.

It might happen that accidentally, the Signalman at A had sent't-he accept signal to B when it was not required and for that reason, the release key 21 is provided, so

that the circuit of the local track relay 8 may be broken at will. The contacts 15 and 29 on the starting signal levers are represented conventionally with the position of the signal, for instance, contact 15 is closed when the signal is at danger and is open when the signal is at clear, while the contact 29is open when the signal is at danger and is closed when-the signal is at clear. 7

It will be understood that the apparatus shown in this figure, only represents that required for one direction of train movement between A and B, only one line 9 however will be required for both directions of train movement, otherwise, with the exception of the bells 11 and S6 and theline indicators 12 and 37, the apparatus shown at A will be also provided at B for the other direction of working and vice versa. This will be readily understood and need only be mentioned.

Referring to Figures 2 and 2 the exam.- ple is shown of the application of the invention to single line working between stations A andB; The track in this case is subdivided a number of timesas follows,

considering the section as beginning from A :To the right of the insulators 40 is the local track circuit 41 covering the fouling points, this extends to the insulator blocks 42. To the right of the insulators 42 is a short stretch of local track 43, while to the right of the insulators 44, the'main track proper 45 begins; this extends tothe insulators 46 after which comes another short stretch of local track 47 similar to the track 43 and then to the right of the insulators 48 is a short stretch of local track 49 covering the fouling points, the insulation of the section occurring at 50. The

tracks 41 and 49 suitably divided asshown by insulators 101, 102, 103 and 104, are

the section B. He thereupon operates his tapper key 55, thereby closing a circuit from earth, battery. 56, armature '82g operated contact of. tapperx key '55-, line; 87, resting V crates the accepting lever 66 thereby closing'the following circuit," Positive pole'ofbattery 65, accepting7, lever i'nth'e' operated position, upper rail of track 45, accepting lever 61 in its resting position, track relayi62, lower rail of ,trackj45 and armatures 63 and. 64 and'their resting'conta'c'ts'to negative pole of battery 65. Then, if there is no train or obstruction-on the track 45, the relay 62 will pick up and at its armature 66 connect battery 67 across the local track 47, so that if this trackis-free thellocal track relay '68 Will pick .up and} at armature 69 lock itself to the battery 67 through thelocal track,"so that the restoration of the accepting lever 60 to its normal position, and the consequent de-energization of-th'ex-relay 62 will be without effect. At armature 70, of relay 68 a. circuit is'al'soclosed for the battery 71, through a number ofparallel paths.- Firstly, the circuit of the signal reverser 7 2, which is of similar construction to reverser 27, is operated,.so that the signal may be lowered. Secondly, the circuit of'the lever lock 73 of the psignahY will-be preparedso that on the signal'man ope'rating the contact maker on the" signal lever, "the signal may be lowered. Thirdly,'the line indicator 74; will energize, thereby causing the indicator to show train accepted. Fou ftlily=,'the permissive relayl75"willfbebperatedwhich at its'arniature 76 'closes" a locking circuit for itself, while atrits armature 77' pr'ep'ares"a c'rcuit for the lever lock78ofthe permissive calling on [arm Z, while at armature 79 the circuit of'the battery 80i's'b10ken'th6r43- by, preventl'nga signalbeing*acceptedin the opposite direction." This' circuit has lready been broken at armature'81" of'relay 68, but this relay only governs a single train, while the relay. 7 5 permits other trains to follow in the same direction,,and consequently is energized for a longer period. Relay 68 at armature 82 connects positive pole of battery to the resting-contactof tapper key 55. Consequently, whenithe signalman atBopcrates histapper ke'yto signify that'he has received notification of the acceptance of a train and has lowered the signal Y, positive current is transmitted over the circuit, battery 83, working contact of rmature 82, 0p-

.erated contactof tapper key 5.5,resting contact of tappe'r" key" 57,;bell 58, line indicator 59 to earth. The bell 58'rings and the line indicator 59 with this current, operates and attracts" its armature; thereby? showing train acce ted-1" Consequently,- ermine-n"- spectively, thereby preventing these ignals being agalnlowered. 'On the train entering the section 47," the relay 68 de-energizes i and, at armature 69, breaks itslocking circuit, so that this can only be reset by the transmission ota 'fresh transient signal over the track 45, atterr'thefitrain has passed therethrough. At armature 70 of'relay 68 the signa l reverser 72 is deenergizedand the signal Y restoresto danger position, at armature 81the circuit connection of; the accegting lever and the battery '80 .is restored butcannot'be completed while the armature; 7 9 is open, at armature82 nega-- tive'battery" is restored tothe lower contact of tapper key 555 On the'train entering-the section and the line indicator? 4:- de-energiz. ing,-so asto' show trainvon line, the ignal man at'B operates-histapper-key 55 thereby transmitting negative current over the line 87"which' causes the indicator--59 to deenergize, thereby also shoWing-",t'rain on line. It should be understood that indicato'r 59 is polarizedand canonlybe deenergized on a reversal of current through its Winding while indicator 74 de-energizes immediately on reversal of current.

Now it maybe desirable to permit=other trains to enterrthe section running in the same directi'on, and 'this may be effected as will be describedg by means-oi" the permissii e relay-75' and the permissive calling on arm Z. Afterithte train has'left the track l9' the relay -SQ again picks: up and .at its armature 85' prepares. a circuit for the: lever lock 7801 the permissive signal Z; It will beun'derstoocl, that this circuit iscompleted through the armature 77 of'the permissive relay 75 which relay is locked operated as previously" described; Consequently, the si'gua l man at B may continue to pass trains through one after another and as long as relay 7 5 is energized it is impossible "for him to'accept a :train in the opposite direction." If however, it desired to change the direction of running;- of the tra-insg then'the signal man at 13 must 0 crate hisrelease button 86 thus breaking t e circuit of' the permissive relay 75 which in turn opens the circuit of the lever lock 78 of the"permissive signal 'Z "at armature 77, and also its own locking circuit at arma tur'e 76; The Signalmanat B may then presshis push button. 88and restore his line indicator to normal showing line closet and he may signal on his tapper key' 55'to the Signalman at A to'do'the same. He is then in'iapositionto accept trains in the opposite direction when the. cycle of op'erati'ons wi-li be; repeated as it previously described. It will be appreciated that by means of the invention, it is impossible for trains to be accepted in opposite directions considerable modifications may be made in the manner of carrying out the invention without departing from the underlying principles.

What I claim as my invention is:

1. A railway signaling system comprising a pair of insulated track rails, a source of electrical energy, switching means for momentarily connecting said source of electrical energy in series with said rails, a device for controlling the passage of a train, electromagnetic means responsive to current transmitted over'said rails for bringing said device to its operative position, locking means for maintaining said device in its operative position independently of said electro-magnetic means, and means controlled by the passage of a train for rendering said locking means inoperative and permitting said device to restore to its normal position.

2. A railway signaling system, comprising a pair of insulated track rails, a source of electrical energy, a manually-operated switch for momentarily connecting said source of electrical energy in series with said rails, a device for controlling the passage of a train, electromagnetic means associated with said rails and responsive to the manual operation of said switch for bringing said device to its operative position, locking means for maintaining said device in its operative position independently of said electromagnetic means, and means controlled by the passage of a train for rendering said locking means inoperative and permitting said device to restore to its normal posi tion. a

3. Arailway signaling system comprising a pair of insulated track rails, a source of electrical energy, switching means for momentarily connecting said source of electrical energy in series with said rails, an electric relay for controlling the passage of a train, electromagnetic means responsive to current transmitted over said rails for bringing said relay to its operative position, locking means for maintaining said relay in its operative position independently of said electro-magnetic means, and means controlled by the passage of a train for rendering said locking means inoperative and permit said device to restore to its normal position 4. A railway signaling system comprismg a pair of insulated track ralls, a source of electrlcal energy, switchmg means for momentary connecting said source of energy in series with said rails, a signal, a device for controlling the operation of said signal, electromagnetic means responsive to the cur rent transmitted over said rails for allowing the movement of said signal to the clear position, locking means for maintaing said signal in its clear position independently of said electromagnetic means, and means controlled by the passage of a train for rendering said locking means inoperative and permitting said signal to restore to the danger position. 7

5. A railway signaling system comprising a pair of insulated track rails, a source of electrical energy, switching means for momentarily connecting said source of electrical energy in serieswith said rails, a device for 6. A railway signaling system comprising a' pair of insulated track rails, a source of electrical energy, switching means for momentarily connecting said source of electrical energy in series with said rails, an electromagnetic device for controlling the passage of a train, electromagnetic means responsive to current transmitted over said rails for bringing said-device to its opera-- tive position, a holding circuit for maintaining said device in its operative position independently of said electromagnetic means, and means controlled by the passage of a train for rendering said holding circuit inoperative and permitting said device to restore to the normal position.

7. A railway signaling system comprising a pair of insulated track rails, a source of electrical energy, an electromagnetic relay connected to said track rails, switching means for connecting said source of energy to said rails to cause the .energization of said relay, and a contact device controlled by said relay to complete a holding circuit for said relay independent of said switching means.

8. A railway signaling system comprising a pair of insulated track rails, a source of electrical energy, an electromagnetic relay connected to said rails, a second relay for connecting said source of energy to said rails to cause the energization of said first relay, and a contact device controlled by said first relay to complete a holding circuit independent of said second relay.

9. A railway signaling systemcomprising a short pair of insulated track rails, a source of electrical energy, an electromagnetic relay connected to said. rails, a second pair of in rail forming the complement of the two firstmentioned track rails, a relay normally connected between said first rail and said thirdrail, a second relay connected between said second rail and said third rail, a source of electrical energy, means for connecting said source of electrical energy between said second rail and said third rail for causing the energization of said second relay, a second source of electrical energy, a contact device controlled by said second relay for connecting said second source of electrical energy between said first and said third rail to cause the energization of said first relay, and a contact device controlled by said first relay to complete a holding circuit for said relay over the circuit including said first and said third mentioned rails.

11. A railway signaling system comprising a pair of insulated track rails, a source of electrical energy, an electromagnetic relay connected to said track rails, switching means for connecting said source of energy to said rails to cause the energization of said relay, a contact device controlled by said relay to complete a holding circuit for'said relay independent of said switching means, a signal, means for operating said signal, and a second contact device controlled by said relay for rendering said signal controlling means effective in bringing-the signal to its off-normal position.

12. A railway signaling system comprising a pair of insulated track rails, two sources of electrical energy, switching means located at each end of said track rails formomentarily connecting the corresponding source of electrical energy in series with said rails, devices for controlling the passage of a train in either direction located one at each end of said insulated track rails, electromagnetic means responsive to currents transmitted over said rails for bringing the corresponding device to its operative position, locking means for maintaining said devices in their operative position independently of said electromagnetic means, means controlled by the passage of a train for rendering said locking means inoperative and permitting said devices to restore to their normal positions, and auXiliarycontact-devices controlled when a switching means is operated to disconnect the corresponding set of electromagnetic means.

1.3; A railwaysignahng system comprising. a pairof insulated track rails, a source 0f electrical energy, switching means for connecting said source of electrical energy in series with said rails, electromagnetic means responsive to current transmitted over said rails, a signaling circuit, other switching means controlled by said electromagnetic means for changing the nature of current transmitted over said signaling circuit.

14. A railway signaling system comprising a pair of insulated track rails, a source of electrical energy, switching means for con 'necting saidsource of electrical energy in series with said rails, a device for controlling the passage of a train, electromagnetic means responsive to current transmitted over said rails for bringing said device to its operative position, locking means'for maintaining said device in its operative position, means controlled by the passage of a train for rendering said lockingimeans inoperative and permitting said device to restore to its normal position, a signaling circuit, two auxiliary sources ot electrical energy, and switching means controlled by said device for connecting either one or the other of said sources of electrical energy in the signaling circuit.

15.A railway signaling system comprising a main insulated track and two local track circuits located at each end of said main track, electromagnetic means and switching means located at each end of said main track, interconnecting means between said switching means and said electromagnetic means whereby the operation of a switching means renders the corresponding electromagnetic means inoperative, contact devices controlled by said electromagnetic means for energizing said local track circuits, and signaling devices controlled by said local track circuits.

16. A railway signaling system comprising a main insulated track and two local track circuits located at each end of said main track, electromagnetic means and switching means located at each end of said main track, and interlocking circuits conswitching means locatedat each end of said main track, interconnecting means between said switching means and said electromagnetic means, whereby the operation of a switching means renders the corresponding electromagnetic means inoperative, contact devices controlled by said electromagnetic means for energizing said local track circuits, signalingdevices controlled by said local track, an auxiliary device operated When one of said track circuits is energized, and a second signaling device controlled by said auxiliary device to permit the passage of successive trains in the same direction after said energized track circuit has been de-energized on the passage of a train.

In testimony whereof I afliX my signature in presence 0 two Witnesses.

ALFRED ERNEST HUDD.

Witnesses:

RICHARD MERCER,

THoMAs HENRY BARNES. 

